Assuming metric units, metre, kilogram and seconds
Best approach: draw a free body diagram and identify forces acting on the child, which are:
gravity, which can be decomposed into normal and parallel (to slide) components
N=mg(cos(theta)) [pressing on slide surface]
F=mg(sin(theta)) [pushing child downwards, also cause for acceleration]
m=mass of child (in kg)
g=acceleration due to gravity = 9.81 m/s^2
theta=angle with horizontal = 42 degrees
Similarly, kinetic friction is slowing down the child, pushing against F, and equal to
Fr=mu*N=mu*mg(cos(theta))
mu=coefficient of kinetic friction = 0.2
The net force pushing child downwards along slide is therefore
Fnet=F-Fr
=mg(sin(theta))-mu*mg(cos(theta))
=mg(sin(theta)-mu*cos(theta)) [ assuming sin(theta)> mu*cos(theta) ]
From Newton's second law,
F=ma, or
a=F/m
=mg(sin(theta)-mu*cos(theta)) / m
= g(sin(theta)-mu*cos(theta)) [ m/s^2]
In case imperial units are used, g is approximately 32.2 feet/s^2.
and the answer will be in the same units [ft/s^2] since sin, cos and mu are pure numbers.
Answer none of the above
Reason - they are adjacent angles
Not vertical
Not complementary
Not supplementary
Answer:
243 ways
Step-by-step explanation:
Calculating the number of posible outcomes:
We have n trials.
Each trial has m possible outcomes.
The total number of outcomes is:
In this question:
5 questions, that is, 5 trials, so 
Each question has 3 options(True, false or unanswered). So 
How many ways?
Answer:
x=c/a-b/a
Step-by-step explanation:
ax+b=c
1) Subtract b from both sides:
ax=c-b
2) Divide both sides by a:
x=c/a-b/a
Answer:
The pebble will hit the ground 8.29 second after it is thrown.
Step-by-step explanation:
Given that,
The height of the pebble after t seconds is given by the equation
h= -16t²+24 t+900.
When the pebble hit the ground, the height of the pebble will be zero.
So putting h=0 in the given equation.
0 = -16t²+24 t+900
⇒-4(4t²-6t-225)=0
⇒4t²-6t-225=0
Applying quadratic formula 
, here a=4, b= -6 and c= -225.
⇒ t = 8.29, -6.79
Since time can not negative.
∴t=8.29 seconds.
The pebble will hit the ground 8.29 second after it is thrown.
