Answer:
(a) Friction force = 50 N
(b) Work done by friction = 300 j
(c) Net work done = 0 j
Explanation:
We have given that the box is pulled by 6 meter so d = 6 m
Force applied on the box F = 60 N
We have have given that velocity is constant so acceleration will be zero
So to applied force will be utilized in balancing the friction force
So friction force 
Work done by friction force 
Work done by applied force 
So net work done = 300-300 = 0 j
Answer:
3.88m/s
Explanation:
Using the law of conservation of momentum
m1u1+m2u2 = (m1+m2)v
m1 and m2 are the masses
u1 and 2 are the initial velocities
v is the final velocity
Given
m1 = 64kg
u1 = 4.2m/s
m2 = 25kg
u2 = 3.2m/s
Required
Final velocity v
Substitute the given values into the formula
64(4.2)+25(3.2) = (65+25)v
268.8+80 = 90v
348.8 = 90v
v = 348.8/90
v = 3.88m/s
Hence the velocity of the kayak after the swimmer jumps off is 3.88m/s
Answer:

Explanation:
We know that from Newton's second law of motion, F=ma hence making acceleration the subject then
where a is acceleration, F is force and m is mass
Also making mass the subject of the formula 
For
and
hence 
Dendrites, the cell body, axon, terminal branches of the axon
It can either be all of them or just 1 and 3