The force applied by the man is 60 N
Explanation:
We can solve this problem by applying Newton's second law, which states that:
(1)
where
is the net force acting on the child+cart
m is the mass of the child+cart system
a is their acceleration
In this problem, we have:
m = 30.0 kg is the mass

And there are two forces acting on the child+cart system:
- The forward force of pushing, F
- The force resisting the cart motion, R = 15.0 N
Therefore we can write the net force as

where R is negative since its direction is opposite to the motion
So eq.(1) can be rewritten as

And solving for F,

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Answer:
33.33 %
Explanation:
given,
error last year = 63
error this year = 42
percent decrease in the error = ?
to find the percentage difference in the error formula used is
= 
= 
= 
= 33.33 %
Percentage decrease in the number of error is equal to 33.33%.
When light hits the boundary between two different materials, it can undergo both reflection and refraction.
Reflection is the change in the direction of the
wave that strikes the boundary between two materials.<span> It involves a change in the direction of waves when they clash with an obstacle.
Refraction involves the change in the direction of waves as they move from one medium to </span><span><span>another followed</span></span><span> by a change in speed and wavelength (this second medium should have different permitivity for the light to change its initial properties.)</span>
Answer:
1.75 m/s
Explanation:
Momentum is conserved.
m₁ u₁ + m₂ u₂ = m₁ v₁ + m₂ v₂
(50 g) (15 m/s) + (600 g) (0 m/s) = (50 g) (-6 m/s) + (600 g) v
v = 1.75 m/s