Answer:
Explanation:
Let t represent the time for Tina to catch David.
Hence, considering the equation of linear motion S = ut + 1/2at^2..... 1
For David u = 28.0 m/s where 'a' is set to nought
S = ut
S = 28t.......2
For Tina consider equation 1
Where acceleration = 2.90m/s^2 and u is set at nought
S = 1/2×2.90 m/s×t^2.......3
Equate 2 and 3
28t = 1.45t^2
Divide through by t
28 = 1.45t
t = 28/1.45
t = 19.31seconds
Now put the value of t into equation 3
S = 1/2×2.90 m/s×t^2.......3
= 1.45×20×20
= 580m
Tina must have driven 580meters before passing David
Considering the equation of linear motion : V^2 = U^2+2as
Where u is set at nought
V^2 = 2as
V^2 = 2×2.9×580
V^2 = 3364
V = √3364
V = 58m/s
Her speed will be 58m/s
Answer:
+9.8m/s^2
Explanation:
The rate of gravity of the object is constant thriughout the surface of the earth.
For falling object, the rate of gravity is positive since the body is coming down (falling)
The rate of gravity is negative if the body is going up
The constant value for acceleration due to gravity is 9.8m.s^2
Since the object is falling, hence the acceleration due to gravity is positive.
Rate of gravity working on the object will be +9.8m/s^2
Answer:
0.33 Amp
8 Watts
Explanation:
The current through the 12 Ω resistor will be given by Ohm's law:
4 V / 12 Ω = 1/3 Amp ≈ 0.33 Amp
The power dissipated on the 2 Ω resistor can be calculated via the formula: 
which gives:
4^2 / 2 = 8 Watts
Answer:
<em>No, a rigid body cannot experience any acceleration when the resultant force acting on the body is zero.</em>
Explanation:
If the net force on a body is zero, then it means that all the forces acting on the body are balanced and cancel out one another. This sate of equilibrium can be static equilibrium (like that of a rigid body), or dynamic equilibrium (that of a car moving with constant velocity)
For a body under this type of equilibrium,
ΣF = 0 ...1
where ΣF is the resultant force (total effective force due to all the forces acting on the body)
For a body to accelerate, there must be a force acting on it. The acceleration of a body is proportional to the force applied, for a constant mass of the body. The relationship between the net force and mass is given as
ΣF = ma ...2
where m is the mass of the body
a is the acceleration of the body
Substituting equation 2 into equation 1, we have
0 = ma
therefore,
a = 0
this means that<em> if the resultant force acting on a rigid body is zero, then there won't be any force available to produce acceleration on the body.</em>
<em></em>
