I assume the block plows into the bank of sand with a velocity of 6 m/s and comes to a stop in 2 s.
Answer:
Explanation:
ACCORDING TO NEWTONS SECOND LAW;
F = mass * acceleration
F = m(v-u/t)
m is the mass = 0.15kg
v is the final velocity = 11m/s
u is the initial velocity = 0m/s
t is the time = 0.015
Substitute;
F = 0.15(11-0)/0.015
F = 0.15(11)/0.015
F = 1.65/0.015
F = 110N
Hence the net force is 110N
Answer:
W = 12.96 J
Explanation:
The force acting in the direction of motion of the sand paper is the frictional force. So, we first calculate the frictional force:
F = μR
where,
F = Friction Force = ?
μ = 0.92
R = Normal Force = 2.6 N
Therefore,
F = (0.92)(2.6 N)
F = 2.4 N
Now, the displacement is given as:
d = (0.12 m)(45)
d = 5.4 m
So, the work done will be:
W = F d
W = (2.4 N)(5.4 m)
<u>W = 12.96 J</u>