A Heat pump takes heat from colder object and transfers it to warmer object.
Answer:
The ball has an initial linear kinetic energy and initial rotational kinetic energy which can both be converted into gravitational potential energy. Therefore the hill with friction will let the ball reach higher.
Explanation:
The ball has an initial linear kinetic energy and initial rotational kinetic energy which can both be converted into gravitational potential energy. Therefore the hill with friction will let the ball reach higher.
This is because:
If we consider the ball initially at rest on a frictionless surface and a force is exerted through the centre of mass of the ball, it will slide across the surface with no rotation, and thus, there will only be translational motion.
Now, if there is friction and force is again applied to the stationary ball, the frictional force will act in the opposite direction to the force but at the edge of the ball that rests on the ground. This friction generates a torque on the ball which starts the rotation.
Therefore, static friction is infact necessary for a ball to begin rolling.
Now, from the top of the ball, it will move at a speed 2v, while the centre of mass of the ball will move at a speed v and lastly, the bottom edge of the ball will instantaneously be at rest. So as the edge touching the ground is stationary, it experiences no friction.
So friction is necessary for a ball to start rolling but once the rolling condition has been met the ball experiences no friction.
Answer:
a pure substance consists only of one element or one compound. a mixture consists of two or more different substances, not chemically joined together.
Explanation:
Hi there!
We can use the kinematic equation:
d = displacement (20 m)
v0 = initial velocity (dropped from rest, so 0 m/s)
t = time (s)
a = acceleration due to gravity (10 m/s²)
Rearrange the equation to solve for time:
Solve using the given values:
Answer:
Explanation:
Given:
the displacement as the function of time:
here time is in seconds and the displacement in meters.
Now we differentiate this eq. of displacement to get the equation of velocity:
According to given the velocity is at some time:
& is the only time for (t>=0) instances when the particle will have a velocity of but in the opposite direction.