Assume the snow is uniform, and horizontal.
Given:
coefficient of kinetic friction = 0.10 = muK
weight of sled = 48 N
weight of rider = 660 N
normal force on of sled with rider = 48+660 N = 708 N = N
Force required to maintain a uniform speed
= coefficient of kinetic friction * normal force
= muK * N
= 0.10 * 708 N
=70.8 N
Note: it takes more than 70.8 N to start the sled in motion, because static friction is in general greater than kinetic friction.
Answer:
is the drop in the water temperature.
Explanation:
Given:
- mass of ice,

- mass of water,

Assuming the initial temperature of the ice to be 0° C.
<u>Apply the conservation of energy:</u>
- Heat absorbed by the ice for melting is equal to the heat lost from water to melt ice.
<u>Now from the heat equation:</u>

......................(1)
where:
latent heat of fusion of ice 
specific heat of water 
change in temperature
Putting values in eq. (1):

is the drop in the water temperature.
Answer:

Explanation:
We have an uniformly accelerated motion, with a negative acceleration. Thus, we use the kinematic equations to calculate the distance will it take to bring the car to a stop:

The acceleration can be calculated using Newton's second law:

Recall that the maximum force of friction is defined as
. So, replacing this:

Now, we calculate the distance:
