A 20-kg block slides down a fixed rough curved track The block has a speed of 5 0 m/s after its height above a horizontal surfac
1 answer:
You might be interested in
Answer:
The friction force is 250 N
Explanation:
The desk is moving at constant velocity. This means that its acceleration is zero: a = 0. Newton's second law states that the resultant of the forces acting on the desk is equal to the product between mass (m) and acceleration (a):
In this case, we know that the acceleration is zero: a = 0, so also the resultant of the forces must be zero:
(1)
We are only interested in the forces acting along the horizontal direction, since it is the direction of motion. There are two forces acting in this direction:
- the pull, forward, F = 250 N
- the friction force, backward,
Given (1), we have
So the force of friction must be equal to the pull:
Answer:
577g
Explanation:
Given parameters:
Temperature change = 5.9°C
Amount of heat lost = 427J
Unknown:
Mass of the block = ?
Solution:
The heat capacity of a body is the amount of heat required to change the temperature of that body by 1°C.
H = m c Ф
H is the heat capacity
m is the mass of the block
c is the specific heat capacity
Ф is the temperature change
Specific heat capacity of lead is 0.126J/g°C
m = H / m Ф
m = = 577g
Mass of the lead block is 577g