A man ran the 200m race within 19.19 seconds. Calculate the speed of the man during the race
1 answer:
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Answer:
The horizontal component of her velocity is approximately 1.389 m/s
The vertical component of her velocity is approximately 7.878 m/s
Explanation:
The given question parameters are;
The initial velocity with which Margaret leaps, v = 8.0 m/s
The angle to the horizontal with which she jumps, θ = 80° to the horizontal
The horizontal component of her velocity, vₓ = v × cos(θ)
∴ vₓ = 8.0 × cos(80°) ≈ 1.389
The horizontal component of her velocity, vₓ ≈ 1.389 m/s
The vertical component of her velocity, = v × sin(θ)
∴ = 8.0 × sin(80°) ≈ 7.878
The vertical component of her velocity, ≈ 7.878 m/s.
Given
Car 1
m1 = 1300 kg
v1 = 20 m/s
m2 = 900 kg
v2 = -15 m/s
(Negative sign shows that direction of car 2 is opposite to car 1)
Procedure
As per the conservation of linear momentum, "The total momentum of the system before the collision must be equal to the total momentum after the collision". And this applies to the perfectly inelastic collision as well. Then the expression is,
Thus, we can conclude that the speed and direction of the cars after the impact is 5.68 m/s towards the first car.
Answer:
20cm
Explanation:
A convex lens has a positive focal length and the object placed in front of it produce both virtual and real image <em>(image distance can be negative or positive depending on the nature of the image</em>).
According to the lens equation
where;
f is the focal length of the lens
u is the object distance
v is the image distance
If the magnification is - 0.6
mag = v/u = -0.5
v = -0.5u
since v = 10cm
10 = -0.5u
u = -10/0.5
u =-20 cm
Substitute u = -20cm ( due to negative magnification)and v = 10cm into the lens formula to get the focal length f
Hence the focal length of the convex lens is 20cm