First law of motion<span>- sometimes referred to as the </span>law<span> of inertia. An object at rest stays at rest and an object in </span>motion<span> stays in </span>motion<span> with the same speed and in the same direction unless acted upon by an unbalanced force.</span>
Let <em>F</em> be the magnitude of the force applied to the cart, <em>m</em> the mass of the cart, and <em>a</em> the acceleration it undergoes. After time <em>t</em>, the cart accelerates from rest <em>v</em>₀ = 0 to a final velocity <em>v</em>. By Newton's second law, the first push applies an acceleration of
<em>F</em> = <em>m a</em> → <em>a</em> = <em>F </em>/ <em>m</em>
so that the cart's final speed is
<em>v</em> = <em>v</em>₀ + <em>a</em> <em>t</em>
<em>v</em> = (<em>F</em> / <em>m</em>) <em>t</em>
<em />
If we force is halved, so is the accleration:
<em>a</em> = <em>F</em> / <em>m</em> → <em>a</em>/2 = <em>F</em> / (2<em>m</em>)
So, in order to get the cart up to the same speed <em>v</em> as before, you need to double the time interval <em>t</em> to 2<em>t</em>, since that would give
(<em>F</em> / (2<em>m</em>)) (2<em>t</em>) = (<em>F</em> / <em>m</em>) <em>t</em> = <em>v</em>
Answer:
The electric field at origin is 3600 N/C
Solution:
As per the question:
Charge density of rod 1,
Charge density of rod 2,
Now,
To calculate the electric field at origin:
We know that the electric field due to a long rod is given by:
Also,
(1)
where
K = electrostatic constant =
R = Distance
= linear charge density
Now,
In case, the charge is positive, the electric field is away from the rod and towards it if the charge is negative.
At x = - 1 cm = - 0.01 m:
Using eqn (1):
(towards)
Now, at x = 1 cm = 0.01 m :
Using eqn (1):
(towards)
Now, the total field at the origin is the sum of both the fields:
Given: Mass m = 0.50 Kg; Force = Weight = mg F = (0.50 Kg)(9.8 m/s²)
F = 4.9 N
Displacement x = 3.0 cm convert to meter x = 0.03 m
Required: Spring constant k = "
Formula: F = kx
k = F/x
k = 4.9 N/0.03 m
k = 163.33 N/m
Refer to the diagram shown below.
By definition momentum = mass * velocity.
Before throwing the ball:
The initial momentum is
P₁ = 0.
After throwing the ball:
Let u = the backward velocity of the quarterback.
The momentum is
P₂ = (0.43 kg)*(15 m/s) + (80 kg)*(- u m/s)
Conservation of momentum requires that
P₂ = P₁
6.45 - 80u = 0
u = 6.45/80 = 0.0806 m/s
Answer: 0.08 m/s backward