Kinetic energy is the energy possessed by a body in motion while potential energy is the energy of a body at rest.
Kinetic energy is given by E=1/2MV² where M is the mass of the body while V is the velocity of the body.
To get mass we can use the formula M= 2 Ek/V² (Making M the subject)
hence mass = (2 ×675)÷35²
= 1.102 kg
Answer: the same direction I.e to the left.
Explanation:
The component perpendicular to the contact surface is such that will stop the relative motion and, in case of elastic collision like here, return the system to the same kinetic energy. So ball hitting immovable surface will have the same speed (magnitude of velocity) as before the collision.
There will also be parallel force caused by friction, but it has to be treated separately for two reasons:
The perpendicular force is limited to coefficient of friction times the normal force. If that is not enough to stop the ball, it will skid on the surface.The perpendicular force, and this depends on the specific geometry, does not pass through the centre of mass of the ball. Therefore it imparts a moment on the ball that causes it to start rotating. And once the ball is rotating so that the point of contact is stationary, there is no momentum to cause any friction force anymore and the friction force disappears and stops decelerating the ball.
So what happens is that the vertical component of the velocity will be reversed, while the horizontal component will be somewhat reduced with the corresponding amount of kinetic energy transferred to energy of rotation. The rotation will always eliminate the friction force before the horizontal component of velocity is zeroed, so the ball will always continue in the same direction, just a bit slower.
If you instead threw an elastic box (which could not start rotating freely) it could actually bounce back.
Answer:
7.9
Explanation:
When we put the metal piece in the liquid (which is in the graduated cylinder), how much it goes up is equal to the volume of the piece we inserted.
So now we know that the volume of that piece of unknown metal is 7mL (which is the same as 7
).
Density is 
.
So the density of that piece of metal is 
Which leaves us with a final density of 7.9
Explanation:
using the formula: S=ut+½gt², where u=0, S=?, g=8m/s², t=10seconds.
S=ut+½gt² ("ut" term will cancel because u=0).
=> S= ½gt²
=>S = ½×8×10²
=>S = 4×100
=>S = 400m .
Therefore, the distance traveled by the body in 10s is 400m.
hope this helps you.
