Answer:
a) Option D
b) Option A
Explanation:
a) Option D
Because a massive car will have more inertia which will make the car move faster but a massive car simultaneously will have more friction thereby restricting its movement in the forward direction. Hence, all the three cars will move equal distance.
b) Option A, Car F
Being most massive car, the frictional force required to stop the car will be highest.
Answer:
The acceleration of the car is
Explanation:
We are assuming rightward coordinate positive and all quantities are along this direction
We know,
where a - acceleration, v=velocity, t=time and x=displacement
multiply by dx in both sides
but we know
Therefore,
Here we integrate both sides with proper limits
x ranges from 0 to 110 as v ranges from 29 to 34
p = 0, r = 110, q = 29, s = 34
a is given as constant thus can be pulled out of the integration
Therefore,
Accelaration of the car is
Note:
Here moving to the right doesn't mean anything significant other than the fact that all quantities are pointing in that direction. Therefore obtained acceleration is also towards the right
If you know equation of motion for constant acceleration as
you can plug in values in this equation to obtain value of a
v - final velocity
u - initial velocity
s - displacement
Sure.
Can I use your answer to part-'a' ?
If the angular acceleration is actually 32 rev/min², than
after 1.2 min, it has reached the speed of
(32 rev/min²) x (1.2 min) = 38.4 rev/min .
Check:
If the initial speed is zero and the final speed is 38.4 rpm,
then the average speed during the acceleration period is
(1/2) (0 + 38.4) = 19.2 rpm average
At an average speed of 19.2 rpm for 1.2 min,
it covers
(19.2 rev/min) x (1.2 min) = 23.04 revs .
That's pretty close to the "23" in the question, so I think that
everything here is in order.
Answer:
12.7m/s
Explanation:
Given parameters:
Mass of the diver = 77kg
Height = 8.18m
Unknown:
Speed of the diver before hitting the water = ?
Solution:
The speed of the diver before hitting the water is the final velocity.
To solve this problem, we use the expression below;
v² = u² + 2gH
v is the final velocity
u is the initial velocity
g is the acceleration due to gravity
H is the height
Now insert the parameters and solve;
v² = 0² + 2 x 9.8 x 8.18
v² = 160.328
v = 12.7m/s