Answer:
The surface gravity g of the planet is 1/4 of the surface gravity on earth.
Explanation:
Surface gravity is given by the following formula:
So the gravity of both the earth and the planet is written in terms of their own radius, so we get:
The problem tells us the radius of the planet is twice that of the radius on earth, so:
If we substituted that into the gravity of the planet equation we would end up with the following formula:
Which yields:
So we can now compare the two gravities:
When simplifying the ratio we end up with:
So the gravity acceleration on the surface of the planet is 1/4 of that on the surface of Earth.
By definition, the gain in PE (potential energy) is
ΔPE = m*g*h
Given:
mg = 40 N (Note that m*g = weight)
h = 5 m
ΔPE = (40 N)*(5 m) =200 J
Answer: 200 J
Answer:
They experience the same magnitude impulse
Explanation:
We have a ping-pong ball colliding with a stationary bowling ball. According to the law of conservation of momentum, we have that the total momentum before and after the collision must be conserved:
where is the initial momentum of the ping-poll ball
is the initial momentum of the bowling ball (which is zero, since the ball is stationary)
is the final momentum of the ping-poll ball
is the final momentum of the bowling ball
We can re-arrange the equation as follows or
which means (1) so the magnitude of the change in momentum of the ping-pong ball is equal to the magnitude of the change in momentum of the bowling ball.
However, we also know that the magnitude of the impulse on an object is equal to the change of momentum of the object:
(2) therefore, (1)+(2) tells us that the ping-pong ball and the bowling ball experiences the same magnitude impulse:
The dotted path is the path of the ball. it reaches it's maximum height at the top where vertical, y-velocity = 0
The initial y-velocity = 19sin(70°)
initial y-velocity = 17.85 m/s
Use one of the kinematic equations with velocity and time. No displacement because we don't want to worry about figuring that out.
v = u - gt
0 = 17.85 - 9.8t
-17.85 = -9.8t
17.85/9.8 = t
1.82 sec = t
