Global warming is what will happen
Answer:
The terrestrial planets in order from smallest to largest are :
Explanation:
Answer:
The time it will take for the object to hit the ground will be 4.
Explanation:
You have:
h(t)=−16t²+v0*t+h0
Being v0 the initial velocity (54 ft/s) and h0 the initial height (40 ft) and replacing you get:
h(t)=−16t²+54*t+40
To know how long it will take for the object to touch the ground, the height h(t) must be zero. So:
0=−16t²+54*t+40
Being a quadratic function or parabola: f (x) = a*x² + b*x + c, the roots or zeros of the quadratic function are those values of x for which the expression is 0. Graphically, the roots correspond to the points where the parabola intersects the x axis. To calculate the roots the expression is used:
In this case you have that:
Replacing in the expression of the calculation of roots you get:
Expresion (A)
and
Expresion (B)
Solving the Expresion (A):
Solving the Expresion (B):
These results indicate the time it will take for the object to hit the ground can be -5/8 and 4. Since the time cannot be negative, then <u><em>the time it will take for the object to hit the ground will be 4.</em></u>
Answer:
b.The frictional force and force exerted by the spring scale on the block, because they are a Newton's third-law pair.
Explanation:
Students connect a spring scale to a block on a rough horizontal surface. The students use the spring scale to measure the magnitude of the horizontal force needed to pull the block at a constant speed. Which of the following statements explains why two forces exerted between objects ar equal in magnitude?
a.A The gravitational and normal forces exerted on the block, because they are a Newton's third-law pair.
b.The frictional force and force exerted by the spring scale on the block, because they are a Newton's third-law pair.
c.The normal force and the frictional force exerted on the block, because objects always exert forces of equal magnitude on each other.
d.The frictional forces that the block and the surface exert on each other, because objects always exert forces of equal magnitude on each other.
solution \
the answer will be B
for a body to travel in a horizontal direction, it must be equal in direction to the frictional force which is in opposite direction to the force applied to move the block.
Also Newton's third law of motion must be obeyed , which states that action and reaction are equal and opposite
Answer:
57 kg
Explanation:
Mass of seesaw = 20 kg
Length of seesaw = 4 m
Mass of child on the longer end = 30 kg
The weight of the seesaw acts at the center i.e. 2m
The algebraic sum of moments of all forces about any point is zero, hence, using the fulcrum as the reference point:
[x * 9.8* 1.5] - [20 * 9.8* (2.5 - 2)] - [30 * 9.8 * 2.5] = 0
=> 14.7x = (20*9.8*0.5) + 735
14.7x = 98 + 735
14.7x = 833
=> x = 833/14.7
x = 57 kg