Answer:
Option 5. 1 and 3
Solution:
The only forces acting on the tennis ball after it has left contact with the racquet and the instant before it touches the ground are the force of gravity in the downward direction and the force by the air exerted on the ball.
The ball after it left follows the path of trajectory and as it moves forward in the horizontal direction the force of the air acts on it.
In the whole projectile motion of the ball, the acceleration due to gravity acts on the ball thus the force of gravity acts on the ball in the downward direction before it hits the ground.
Answer:
a)V=18.35 m/s (South -East)
b) t =7.41 m/s
c)D= 66.70 m
Explanation:
Given that
Velocity of boat in east direction = 16 m/s
Velocity of river = 9 m/s
a)The resultant velocity V
V=18.35 m/s (South -East)
b)
We know that
Distance = Velocity x time
Lets t time takes to cross the river
136 = 18.35 x t
t =7.41 m/s
c)
The distance covered downstream
We know that
Distance = Velocity x time
t= 7.41 s
D= 7.41 x 9 m
D= 66.70 m
Answer:
F = - 3.56*10⁵ N
Explanation:
To attempt this question, we use the formula for the relationship between momentum and the amount of movement.
I = F t = Δp
Next, we try to find the time that the average speed in the contact is constant (v = 600m / s), so we say
v = d / t
t = d / v
Given that
m = 26 g = 26 10⁻³ kg
d = 50 mm = 50 10⁻³ m
t = d/v
t = 50 10⁻³ / 600
t = 8.33 10⁻⁵ s
F t = m v - m v₀
This is so, because the bullet bounces the speed sign after the crash is negative
F = m (v-vo) / t
F = 26*10⁻³ (-500 - 640) / 8.33*10⁻⁵
F = - 3.56*10⁵ N
The negative sign is as a result of the force exerted against the bullet
When the initial speed given is 7.5m/s at an angle of 27° , ball will go
4.637 meters.
Assume no air opposition to the ball ;
Vertical component of ball is sin 27° = 0.453
0.453* 7.5 = 3.404 meters /sec
Time taken to reach ground is :
3.404 = -3.404+9.8*t
t= 6.808/9.8= 0.694 sec
Horizontal component is 7.5*cos27°= 6.682m/s
Distance = speed * time
=6.682 * 0.694
=4.637 meters
Horizontal distance it can cover in 0.694 sec is 4.637 meters
So range of ball is 4.637 meters.
Form of motion experienced by an object or particle that is projected near surface of the earth and moves along a curve is called Projectile motion. Three types of projectile motion are Horizontal projectile motion. Oblique projectile motion and Projectile motion on an inclined plane.
To know more about projectile motion, refer
brainly.com/question/24216590
#SPJ13
