An example for curvilinear motion.

vovangra [49]

Answer:

acceleration 8 km/h/s south

Explanation:

First of all, let's remind that a vector quantity is a quantity which has both a magnitude and a direction.

Based on this definition, we can already rule out the following two choices:

distance: 40 km

speed: 40 km/h

Since they only have magnitude, they are not vectors.

Then, the following option:

velocity: 5 km/h north

is wrong, because the car is moving south, not north.

So, the correct choice is

acceleration 8 km/h/s south

In fact, the acceleration can be calculated as

$a=\frac{v-u}{t}$

where

v = 40 km/h is the final velocity

u = 0 is the initial velocity

t = 5 s is the time

Substituting,

$a=\frac{40 km/h-0}{5 s}=8 km/h/s$

And since the sign is positive, the direction is the same as the velocity (south).

7 0

3 years ago

Sergeeva-Olga [200]

Answer:

Explanation:

The two cyclists travel at the same speed on level ground, as they approach a low hill and decide to coast up instead of hard pedaling. At the top of the hill, as bike "B" will have a larger speed, as compared to the bike "A".Due, to the effect of having smaller moment of inertia, I=m×r².

Having no friction nor air resistance, and all the wheels roll on the ground without slipping. While, the B have larger speed,v due to the fact that bike "B" will have a larger speed,"v" as compared to the bike "A".

3 0

3 years ago

MrMuchimi

Answer:

W=700 Joule

Explanation:

Physics Work

Is the dot product of the force vector by the displacement vector

$W=\vec F \cdot \vec r$