Question

Please solve it on a paper or copy and send me.....
It's really urgent:-
1) If an object of Mass m travels with 25km/hr and changes it's speed to x km/hr in 2 min. During tis it covers 1 km.
Calculate f and x.
2) What is the unit of:-
(a) Force
(b) Velocity
(c) Momentum
(d) acceleration

3) Explain Newton's law of motion

4) Define Momentum

fast please: |
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Answer 1

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SOLUTION-1 :-

Mass of the object = m kg

Initial velocity(u) = 25 km/h = 6.94 m/s

Final velocity(v) = x m/s

Time(t) = 2 mins = 120 secs

Distance covered(s) = 1 km = 1000 km

We know that,

$\displaystyle{\sf{s=ut+\frac{1}{2}at^2 }}\\\\\displaystyle{\sf{\implies 1000=6.94\times120+\frac{1}{2}\times a \times(120)^2 }}\\\\\displaystyle{\sf{\implies 1000=832.8+\frac{1}{2}\times14400a }}\\\\\displaystyle{\sf{\implies 1000=832.8+7200a}}\\\\\displaystyle{\sf{\implies 167.2=7200a}}\\\\\displaystyle{\sf{\implies a=0.023\ m/s^2}}$

Now, we also know that,

$\displaystyle{\sf{v=u+at}}$

$\displaystyle{\sf{\implies v=x=6.94+(0.023 \times 120)}}\\\\\displaystyle{\sf{\implies x=6.94+2.76}}\\\\\displaystyle{\sf{\implies x=9.7\ m/s}}$

Now, F = ma

⇒F = m × 0.023

⇒F = 0.023m

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SOLUTION-2 :-

(a) Unit of Force is Newton(N) or kgms⁻².

(b) Unit of Velocity is meter per second (m/s).

(c) Unit of Momentum is kgms⁻¹.

(d) Unit of Acceleration is m/s².

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SOLUTION-3 :-

There are three of Newton’s laws of motion. In these three laws of motion, he explained the relationship between forces acting on the body and the motion of the body. Newton’s three laws are as stated below:

• An object continues to be under the state of uniform motion unless an external force acts on it.

• Force is a product of mass and acceleration.

• For every action, there is an equal and opposite reaction.

Newton’s first law of motion is also known as the law of inertia. In Newton’s second law of motion, the velocity is constant. Newton’s third law of motion is also known as conservation of momentum.

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SOLUTION-4 :-

Momentum is the tendency of the object to be in motion and therefore is a vector quantity. It is determined by the product of the mass of the object and its velocity. If both the objects are not experiencing any external forces, then the total momentum of the objects before and after the interaction is the same. This relation under the fundamental law of physics is known as the conservation of momentum.

Momentum (P) = mass (m) x velocity (v)

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