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a particle is moving along a straight line with the acceleration a= (15 t− 7t/3) ft/s2, where t? is in seconds. determine the velocity and the position of the particle as a function of time when t= 0, v= 0 and x= 15 ft.
Two blocks, with masses 4.00 kg and 8.00 kg are connected by a string and slide down a
30 inclined plane (see figure). The coefficient of kinetic friction between the 4.00 kg block and the
plane is 0.25; that between the 8.00 kg block and the plane is 0.35. Calculate
a) the acceleration of each block
b) the tension in the string
A particle of mass m has speed v = c/x, where c is a constant and x is the displacement. At t=0, x=
x Find the force
a) F(x)
b) F(t)
A particle is moving in a central force field r= ke^ax
(i) Find the force law
(ii) Find x(t)
(iii) Find the total energy
An ice glider is traveling 35 degrees W of S at 6 m/s when the wind exerts a force of 860 N 18 degrees N of W for three seconds. The mass of the glider is 215 kg. Complete the chart below and then answer the questions that follow.
t(s): 0, 1, 2, 3
East v (m/s): --3.44, t = 1, t = 2, t = 3
North v (m/s): --4.92, t = 1, t = 2, t = 3
What is the glider's initial kinetic energy?
What is the glider's kinetic energy at t = 2?
How much energy does the wind put into the glider in the 3 s interval?
What is the glider's average speed for the three second interval?
What is the glider's average velocity for the three second interval?
Represent graphic the force of Weight of a man. Is the Weight force of a man on Earth the same if the man is sitting vertical or horrizontal?
An ice glider, that has a mass of 1640 kg, is initially moving at 20 m/s NW. A wind accelerates the glider at 2.5 m/s? 20° E of N for eight second. Then the wind shifts to 48°E of N accelerating the glider at 1.8 m/s for 11 seconds. 1) What is the glider's initial kinetic energy? 2) What is the glider's velocity at t= 8 s? 3) How much energy did the wind transfer to the glider during the 8 s? 4) What was the glider's velocity after the 11s the second wind gust was active? 5) How much energy did the wind transfer to the glider during the 19s? 6) What was the glider's average speed from t = 0 s to t = 19 s? 7) What was the glider's displacement from t = 0 s to t = 19 s? 8) What was the glider's average velocity from t = 8stot=198? 9) What was the glider's final kinetic energy? 10) A student contends that the glider will have the largest force at t = 19 s since it has the most kinetic energy at that time. Is this contention reasonable? Explain.
What is the airspeed of a laden swallow?
An ice glider, that has a mass of 1640 kg, is initially moving at 20 m/s NW. A wind accelerates the glider at 2.5 m/s? 20° E of N for eight second. Then the wind shifts to 48°E of N accelerating the glider at 1.8 m/s for 11 seconds. 1) What is the glider's initial kinetic energy? 2) What is the glider's velocity at t= 8 s? 3) How much energy did the wind transfer to the glider during the 8 s? 4) What was the glider's velocity after the 11s the second wind gust was active? 5) How much energy did the wind transfer to the glider during the 19s? 6) What was the glider's average speed from t = 0 s to t = 19 s? 7) What was the glider's displacement from t = 0 s to t = 19 s? 8) What was the glider's average velocity from t = 8stot=198? 9) What was the glider's final kinetic energy? 10) A student contends that the glider will have the largest force at t = 19 s since it has the most kinetic energy at that time. Is this contention reasonable? Explain.
An apple is falling down from a height of 20m and then hit a
person. Assume that the mass of the apple is 200g. The
duration of impact is 0.001 sec and that the area of the
bone is 1 cm(square). (a) Calculate the impulsive force applied to
the person. (b) If the rupture strength for body tissue is
about 5 X 1000000dyn/cm(sqare), will the impact force lead to serious
injury for the person?
