Answer:
(a) Projectile B will travel 4 times as far as projectile A prior to landing
Explanation:
Initial velocity = v
Angle at which the projectile is shot at = θ
g = Acceleration due to gravity
Range of a projectile is given by
When Initial velocity = v
When Initial velocity = 2v
Dividing the equtions, we get
Here, the angle at which the projectiles are fired at are equal.
Hence, projectile B will travel 4 times as far as projectile A prior to landing
Answer:
The work done required on the coin during the displacement is 21.75 w.
Explanation:
Given that,
A coin slides over a friction-less plane i.e friction force = 0.
The co-ordinate of the given point is (1.40 m, 7.20 m).
The position vector of the given point is represented by .
The displacement of the coin is
The force has magnitude 4.50 N and its makes an angle 128° with positive x axis.
Then x component of the force = 4.50 cos128°
The y component of the force = 4.50 sin128°
Then the position vector of the force is
We know that,
work done is a scalar product of force and displacement.
=(-2.77×1.40+ 3.56×7.20) w
=21.75 w
The work done required on the coin during the displacement is 21.75 w.
Answer:
θ₁ = 0.5 revolution
Explanation:
We will use the conservation of angular momentum as follows:
where,
I₁ = initial moment of inertia = 18 kg.m²
I₂ = Final moment of inertia = 3.6 kg.m²
ω₁ = initial angular velocity = ?
ω₂ = Final Angular velocity = = 1.67 rev/s
Therefore,
where,
θ₁ = revolutions if she had not tucked at all = ?
t₁ = time = 1.5 s
Therefore,
<u>θ₁ = 0.5 revolution</u>