1) Read the scenario.
A car starts 10 m north of a reference point. It moves at a constant velocity over the next 5 s, reaching a position of 10 m south of the reference point.
What is the car’s average velocity?
0 m/s
4 m/s north
2 m/s south
4 m/s south
-I know that v=d/t but I do not know what to do after I get 2 m/s n with it reaching a position of 10 m south of the reference point.
2)
A 60 kg skydiver is falling at a terminal velocity of 50 m/s.
Calculate the amount of gravitational force acting on the skydiver.
3000 N
9.8 N
588 N
0 N
Could anyone help with the equation I would need to do for this one?
3)
Study the scenario.
An ice block in motion begins to slide up an icy hill. The system consists of the block, the hill, and the Earth. (There is no friction.)
Which choice best describes the changes in kinetic and potential energy?
The kinetic energy remains constant as the block moves up the hill because its speed remains constant. The potential energy increases because the block’s height relative to its starting position increases. The total energy increases.
The kinetic energy decreases as the block moves up the hill because it slows down. The potential energy increases because the block’s height relative to its starting position increases. The total energy remains constant.
The kinetic energy remains constant as the block moves up the hill because its speed remains constant. The potential energy remains constant because the block remains on the ground the entire time. The total energy remains constant.
The kinetic energy increases as the block moves up the hill because it speeds up. The potential energy increases because the block’s height relative to its starting position increases. The total energy increases.
I think its D, but I am not sure.
1) To calculate the average velocity, consider the total distance traveled and total time. The car started 10 m north and ended up 10 m south, so the total distance traveled was 20 m. The time taken was 5 s. So, the average velocity is:
v = d/t = 20m / 5s = 4 m/s
Since the car moves from north to south, the correct answer is 4 m/s south.
2) To calculate the gravitational force acting on the skydiver, use the equation:
F = m * g
where F is the gravitational force, m is the mass of the skydiver, and g is the acceleration due to gravity (approximately 9.8 m/s²).
F = 60 kg * 9.8 m/s² = 588 N
So, the gravitational force acting on the skydiver is 588 N.
3) The correct answer is:
The kinetic energy decreases as the block moves up the hill because it slows down. The potential energy increases because the block’s height relative to its starting position increases. The total energy remains constant.
As the block moves up the hill, it loses kinetic energy (it slows down) but gains potential energy (due to increased height). In a frictionless system, the total mechanical energy (kinetic + potential) remains constant.
1) The car starts 10 m north of the reference point and ends up 10 m south of the reference point. So, the total displacement is 10 m + (-10 m) = 0 m. The time taken is 5 s. Therefore, the average velocity is 0 m/5 s = 0 m/s. So, the answer is 0 m/s.
2) The gravitational force acting on an object can be calculated using the equation F = m * g, where F is the force, m is the mass of the object, and g is the acceleration due to gravity. In this case, the mass of the skydiver is given as 60 kg. The gravitational force is 60 kg * 9.8 m/s^2 = 588 N. So, the answer is 588 N.
3) The correct answer is D. As the ice block moves up the hill, its kinetic energy increases because it speeds up. The potential energy also increases because the block's height relative to its starting position increases. Since both kinetic and potential energy increase, the total energy increases.
1) To find the average velocity of the car, we need to divide the total displacement by the total time. In this scenario, the car starts 10 m north and ends 10 m south, resulting in a total displacement of 20 m. The total time taken is 5 seconds. Now we can calculate the average velocity using the formula v = d/t:
Average velocity = total displacement / total time
= 20 m / 5 s
= 4 m/s south
So, the correct answer is 4 m/s south.
2) The gravitational force acting on the skydiver can be calculated using the formula F = mg, where F represents the force, m represents the mass, and g represents the acceleration due to gravity. In this scenario, the mass of the skydiver is given as 60 kg and the terminal velocity is 50 m/s. However, the terminal velocity is the maximum velocity at which the skydiver falls, so the gravitational force is actually acting on the skydiver to reach this terminal velocity. Therefore, we can calculate the gravitational force using the given mass and acceleration due to gravity:
Gravitational force = mass x acceleration due to gravity
= 60 kg x 9.8 m/s^2
= 588 N
So, the correct answer is 588 N.
3) In this scenario, we need to consider the changes in kinetic and potential energy as the ice block moves up the hill.
As the block moves up the hill, its speed decreases because it is moving against the force of gravity. Therefore, kinetic energy decreases. At the same time, the block's height relative to its starting position increases. As the potential energy of an object depends on its height, the potential energy of the block increases. The total mechanical energy, which combines kinetic and potential energy, remains constant in the absence of other forms of energy transfer or external forces.
Therefore, the correct answer is:
The kinetic energy decreases as the block moves up the hill because it slows down. The potential energy increases because the block’s height relative to its starting position increases. The total energy remains constant.
1) To find the car's average velocity, you need to calculate the displacement and divide it by the time taken. Given that the car starts 10 m north and ends 10 m south from the reference point, the displacement is (-10 m - 10 m) = -20 m. The time taken is 5 seconds.
Average velocity = displacement / time taken = -20 m / 5 s = -4 m/s
Therefore, the car's average velocity is 4 m/s south.
2) To calculate the amount of gravitational force acting on the skydiver, you can use the equation:
Gravitational force = mass × acceleration due to gravity
Given that the mass of the skydiver is 60 kg and the acceleration due to gravity is approximately 9.8 m/s^2, you can calculate:
Gravitational force = 60 kg × 9.8 m/s^2 = 588 N
Therefore, the amount of gravitational force acting on the skydiver is 588 N.
3) In this scenario, as the ice block slides up the icy hill without friction, its kinetic energy and potential energy will change.
The correct answer is A. The kinetic energy remains constant as the block moves up the hill because its speed remains constant. The potential energy increases because the block's height relative to its starting position increases. The total energy increases. Since there is no external work being done, the total energy of the system remains constant, but it is converted between potential and kinetic energy.
So, the correct choice is A.