5.38
21 divided by 3.9 is 5.38 and the equation for acceleration is change in velocity divided by time
<span>It bounces back toward a single spot. This is how the focusing mirrors on headlights work</span>
#1
for the block of mass 5 kg normal force is given as


friction force is given as


Net force is given as


now we know that



#2
Normal force is given as



now we know that


as object moves with constant velocity

now for coefficient of friction we can use



#3
net force upwards is given as

mass is given as

now as per newton's law we can say



#4
As we know that when block is sliding on rough surface
part a)
net force = applied force - frictional force




part b)
for coefficient of friction we can use


here normal force is given as

now we have

#5
if an object is initially at rest and moves 20 m in 5 s
so we can use kinematics to find out the acceleration



now net force is given as


#6
an object travelling with speed 25 m/s comes to stop in 1.5 s
so here acceleration of object is given as


now the force is gievn as


Answer:
emf = 0.02525 V
induced current with a counterclockwise direction
Explanation:
The emf is given by the following formula:

(1)
ФB: magnetic flux = BA
B: magnitude of the magnetic field = 1.00T
A2: final area of the loop; A1: initial area
t2: final time, t1: initial time
You first calculate the final A2, by taking into account that the circumference of loop decreases at 11.0cm/s.
In t = 4 s the final circumference will be:

To find the areas A1 and A2 you calculate the radius:
r1 = 0.261 m
r2 = 0.190 m
Then, the areas A1 and A2 are:

Finally, the emf induced, by using the equation (1), is:

The induced current has counterclockwise direction, because the induced magneitc field generated by the induced current must be opposite to the constant magnetic field B.
Answer:
25 seconds!
Explanation:
I just had to find what number to multiply 4 to get 100 and it was 25
4x25=100
Or you could do the easier way by dividing 100 by 4 which has the same answer: 25
100÷4=25